src/assets/christmastree.png by yd CC-BY 3.0 https://opengameart.org/content/snow (changed)
src/assets/df_dk_0000787_32e.png Public Domain http://www.deutschefotothek.de/documents/obj/70301690
src/assets/df_single.png Public Domain http://www.deutschefotothek.de/documents/obj/70301690
Foto: SLUB Dresden / Henrik Ahlers CC-BY-SA https://de.m.wikipedia.org/wiki/Datei:Aussenaufnahme_der_SLUB_Dresden_(17932774691)_(2).jpg

src/assets/snow_on_stones.png by yd CC-BY 3.0 https://opengameart.org/content/snow
src/assets/SnowyTrees.png by yd CC-BY 3.0 https://opengameart.org/content/snow
src/assets/snowman.png by Azzarc CC0 https://opengameart.org/content/snowman-2

src/assets/WinterDeko2.png: blankhouse3x2 by Shepardskin CC0 https://opengameart.org/content/house-sets
			    logo candy by Melle CC0 https://opengameart.org/node/108667
			    holiday-pack 2016 by Kenney CC0 https://opengameart.org/content/holiday-pack-2016

Cainos asset pack:
src/assets/TX Tileset Grass.png by cainos https://cainos.itch.io/pixel-art-top-down-basic
src/assets/TX Shadow Plant_grey51.png by cainos https://cainos.itch.io/pixel-art-top-down-basic (changed)
src/assets/TX Plant.png by cainos https://cainos.itch.io/pixel-art-top-down-basic 
src/assets/TX Probs.png by cainos https://cainos.itch.io/pixel-art-top-down-basic 
                             cainos asset pack can be used in both free and commercial projects. You can modify it to suit your own needs. Credit is not needed but appreciated.  You may not redistribute it or resell it.